Generally, electric appliances which are used in a house, an office, or a factory are classified into two groups, i.e., those which need to be supplied with power all the time such as a refrigerator and those which need to be supplied with power on occasion such as a television, an audio, and a computer monitor.
However, even in the latter type of appliances, most of them are connected to a power source all the time since the power source is usually connected to a outlet located on a wall or a floor so the blocking of the power is inconvenient.
FIG. 1 shows the construction of a power supply system for an electric appliance 200. As shown, an electric energy is supplied to an appliance by connecting a plug of the appliance to an alternating current power or a general outlet 100. In most cases, the appliance is continuously connected with the power due to the inconvenience of blocking the power.
Accordingly, due to such continuous connection, electric power has been consumed unnecessarily and there exists a possibility of a big fire. The total sum of the wasted electric power nationwide is considerable.
In order to overcome such problem caused due to the current leakage of an appliance, a multi-type standby current intercepting multi-tap has been rolled out. This type of outlet strip detects whether or not a user operates a computer by using the clock signal and the data signal of a mouse and a keyboard, which are the input devices of a computer. If it is determined that the computer is not being used, the power is not to be supplied to the peripherals.
If a user reuses the computer, the power is supplied to the peripherals again. By doing such, the power can be saved when a user is not using the computer but the computer is on.
To avoid the current leakage, a outlet including a control module for interlocking the mainframe and the peripherals of a computer is also used. Herein, according to the interlocking control, the main frame of a computer is connected to the main outlet and the peripherals (for example, a printer and a monitor) are connected to the auxiliary outlets. Thus, if the mainframe of the computer is turned off, the multi-tap detects and intercepts the standby power supplied to the peripherals so that the power can be saved.
On the contrary, according to the single-acting control, appliances are individually connected to the auxiliary outlets regardless of the main outlet, and multi-tap detects and supplies/intercepts the standby electric power. Hereinafter, the interlocking control and the single-acting control will be described.
Even remote-control power-saving outlet devices are widely used for the aforementioned type of multi-tap.
However, in the case of the outlet employing the interlocking control function, it has deficiency in precisely detecting the peripherals and sensitively controlling the on/off operation.
Also, the above conventional multi-tap has the problem in that it does not work (i.e., the interlocking control) if the current capacity is used for different appliances at the same time.